#include <iostream>


using namespace std;


int main(int argc, char **argv){

    int a;
    int num = 0;
    int *p = &num;

    p[-1] = 2;          //out of bound
    p[0] = 3;           //okay
    p[1] = 4;           //out of bound

    cout << "num = " << num << endl;


    return 0;
}